RKI Instruments 65-2397RK User Manual

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65-2397RK

Part Number: 71-0185RK Revision: B Released: 7/18/14

CO2 Transmitter

Operator’s Manual

RKI Instruments, Inc.

www.rkiinstruments.com

WARNING

Read and understand this instruction manual before operating transmitter. Improper use of the transmitter could result in bodily harm or death.

Periodic calibration and maintenance of the transmitter is essential for proper operation and correct readings. Please calibrate and maintain this tra nsmitt er regula rly! Frequency of calibration depends upon the type of use you have and the sensor types. Typical calibration frequencies for most applications are between 6 and 12 months, but can be required more often or less often based on your usage.

65-2397RK CO2 Transmitter

Product Warranty

RKI Instruments, Inc. warrants gas alarm equipment sold by us to be free from defects in materials, workmanship, and performance for a period of one year fr o m date of shipment from RKI Instruments, Inc. Any parts found defective withi n tha t period will be repaired or replaced, at our option, free of charge. This warranty does not apply to those items which by their nature are subject to deterioration or consumption in normal ser v ice, and which must be cleaned, repaired, or replaced on a routine basis. Examples of such items are:

W arranty is voided by abuse including mechanical damage, alteration, rough handling, or repair procedures not in accordance with the operator’s manual. This warranty indicates the full extent of our liability , a nd we are not r esponsible for removal or r eplacement costs, local repair costs, transportation costs, or contingent expenses incurred without our prior approval.

a) Absorbent cartridges d) Batteries b) Pump diaphragms and valves e) Filter elements c) Fuses

THIS WARRANTY IS EXPRESSLY IN LIEU OF ANY AND ALL OTHER WARRANTIES AND REPRESENTATIONS, EXPRESSED OR IMPLIED, AND ALL OTHER OBLIGATIONS OR LIABILITIES ON THE PART OF RKI INSTRUMENTS, INC. INCLUDING BUT NOT LIMITED TO, THE WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL RKI INSTRUMENTS, INC. BE LIABLE FOR INDIRECT, INCIDENTAL, OR CONSEQUENTIAL LOSS OR DAMAGE OF ANY KIND CONNECTED WITH THE USE OF ITS PRODUCTS OR FAILURE OF ITS PRODUCTS TO FUNCTION OR OPERATE PROPERLY.

This warranty covers instruments and parts sold to users by authorized distributors, dealers, and representatives as appointed by RKI Instruments, Inc.

We do not assume i ndemnification for a ny accident or damag e c au sed by the operatio n of this gas monitor, and our warranty is limited to the replacement of parts or our complete goods.

65-2397RK CO2 Transmitter

Table of Contents

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

CO2 Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Junction Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Mounting the CO2 Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Wiring the CO

Startup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Setting the Zero Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Replacing Components of the CO

Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Preparing for Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Setting the Zero Reading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Setting the Response Reading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Returning to Normal Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

65-2397RK CO2 Transmitter

Overview

This manual describes t he 65 -23 97R K CO2 transmitter. This manual also des cribes how to install, start up, configure, maintain, and calibrate the transmitter when it is used with a

gas monitoring controller. A parts list at the end of this manual lists replacement parts and accessories for the CO

Specifications

Table 1 lists specifications for the CO2 transmitter.

transmitter.

Table 1:Specifications

Description Specification

Target Gas Carbon Dioxide (CO Sampling Method Diffusion

Signal Output 4 to 20 mA Detection Range 65-2397RK-02: 0-5,000 ppm

65-2397RK-03: 0-5% Volume 65-2397RK-05: 0-50% Volume

65-2397RK-10: 0-100% Volume Response Time 90% in 45 seconds Operating Temperature

Accuracy ± 5% of reading or ± 2% of full scale (whichever is gr eater)

-4°F to 122°F (-20°C to 50°C)

)

W ARNING: When using the 65-2397RK, you must follow the instructions and warnings

in this manual to assure proper and safe operation of the 65-2397RK and to minimize the risk of personal injury. Be sure to maintain and period ically calibrate the 65-2397RK as described in t hi s manual.

65-2397RK CO2 Transm itter • 1

Description

This section describes the components of the CO2 transmitter. The transmitter is a 4 - 20 mA type detector head. It consists of the CO

detector, amplifier, and junction box.

Factory Adjust Pot

Span Pot

Ze ro P ot

Factory Adjust Pot

Jumper Pins,

actory UseOnly

+ Test Point

- Test Point

Controller Terminal Strip

Amplifier

SPAN

ZERO

Sensor

Current

PWR / SIG

LEL

R W B

Detector Termina Strip

J-Box

IR CO2Detector

Figure 1: CO2 Transmitter Component Location

Infrared CO2 Detector

The CO2 detector consists of the detector housing body, detector housing cap, cap gasket, and the plug-in sensor.

2 • 65-2397RK CO2 Transmitter

Detector Housing Body

Cap Gasket

Plug-In CO2 Sensor

Sensor Retainer

Detector Housing Cap

Hydrophobic Membrane

Figure 2: CO2 Detector Component Location

Detector Housing Body

The detector housing body protects the electronic components within the housing. Use the mounting threads at the top of the housing to screw the CO

hub on the bottom of the junction box. Four color coded leads, red, white, green, and black, extend from the other end of the detector. The leads allow you to connect the detector to the amplifier.

The housing includes three sockets installed on a circuit board. These sockets accept the plug-in sensor’s three pins to provide an electrical connection for the sensor. The circuit board with the sockets conditions the sensor’s signal before the signal reaches the amplifier.

Housing Cap & Cap Gasket

The housing cap screws onto the detector housing. It retains the plug-in sensor and protects it from damage. A foam gasket is installed inside the ho using cap that seals against the sensor face. A hydrophobic membrane on the outside of the cap face keeps water and particulates away from the sensor face behind the cap. Unscrew the detector cap to access the plug-in sensor for maintenance or replacement. A cap gasket seals the interface between the housing and cap.

Plug-In CO

The plug-in sensor is secured in the detector assembly by the housing cap. The se nsor produces a millivolt output that corresponds to the detection range of the transmitter.

Sensor

detector into the 3/4” NPT

Amplifier

The amplifier converts the electrical output from the detector to a 4 to 20 mA signal that corresponds to the detection range and transmits the signal to a gas monitoring controller . A foam gasket that orients the amplifier and keeps it from rotating is installed on the

65-2397RK CO2 Transm itter • 3

bottom of the amplifier. The amplifier includes the controller terminal strip, detector terminal strip, span pot, zero pot, and test points (see Figure 1) .

Controller Terminal Strip

The controller terminal strip is a three position plug-in style terminal strip located near the top of the amplifier. Use the controller terminal strip to wire the CO

transmitter to a

controller.

Detector Terminal Strip

The detector terminal strip is a four position plug-in style terminal strip located below the controller terminal strip. Use the detector terminal strip to connect the CO

transmitter to

the amplifier.

NOTE: The IR CO2 detector is factory-wired to the detector terminal strip. See “Wiring

the CO

Transmitter to a Controller” on page 6 for all wiring procedures related

to the transmitter.

Zero Pot

The zero pot is located in the upper left corner of the amplifier (see Figure 1). Use a small flat blade screwdriver to turn the zero pot’s adjustment screw and adjust th e amplifier’s target gas-free output during the start-up and calibration pr ocedures. Turn the adjustment screw clockwise to increase the zero output and counterclockwise to decrease the zero output.

Span Pot

The span pot is located to the right of the zero pot (see Figure 1). Use a small flat blade screwdriver to turn the span pot’s adjustment screw and adjust the amplifier’s gas response output during the calibration procedure. Turn the adjustment screw clockwise to increase the gas response and counterclockwise to decrease the gas response.

CAUTION: The amplifier includes two additional potentiometers. They are factory-set. Do not

adjust them.

Test Points

The test points are on the left side of the amplifier (see Figure 1). The test points produce a 100 mV to 500 mV output that corresponds to the transmitter’s 4 to 20 mA output. Use the test points and a voltmeter to measure the amplifier’s output during the start-up and calibration procedures. The black test point in the lower left corner is the negative (-) test point and the red test point below the zero pot is the positive (+) test point.

Junction Box

Use the junction box to install the transm itter at a mounting site that is remote from the controller. The junction box protects the amplifier and wiring connections made to the amplifier. Use the top 3/4’’ conduit hub to connect wiring from the amplifier to the controller. Use the cover on the front of the junction box to access the interior of the junction box. The detector and amplifier are factory installed in the junction box. Three spacers installed on the back of the junction box control the distance of the junction box from a mounting surface and ensure that there is enough room to install a calibration cup on the detector during calibration.

4 • 65-2397RK CO2 Transmitter

Installation

3.10

This section describes procedures to mount the CO2 transmitter in the monitoring environment and wire the transmitter to a controller.

Mounting the CO2 Transmitter

1. Select a mounting site that is representative of the monitoring environment. Consider the following when you select the mounting site.

• Select a site where the transmitter is not likely to be bumped or disturbed. Make

sure there is sufficient room to perform start-up, maintenance, and calibration procedures.

• Mount the transmitter at least six feet from the floor to minimize the possibility of

someone breathing on the unit. The exhaled CO

may cause an alarm.

3/4 NPT

Female

.75

.38

3.65

6.80 MAX Rubber

Spacers, 3X

J-Box

IR CO2

Detector

1 1/2-2 0 Thre a d for

Calibration Cup

Figure 3: Mounting the CO2 Transmitter

2. At the monitoring site you select, hang or mount th e jun c tion box with the detector facing down (see Figure 3).

65-2397RK CO2 Transm itter • 5

Wiring the CO2 Transmitter to a Controller

WARN ING: Alway s verify that the power to the controller is off before you make

wiring connections.

1. Turn off the controller.

2. Turn off or unplug power to the controller.

3. Remove the junction box cover.

4. The detector leads are factory wired. Verify that the detector leads are wired to the amplifier’s detector terminal strip as shown in Figure 4.

5. To gain access to a plug-in terminal strip for wiring, pull it out of its sock et by grasping the terminal strip and pulling. The detecto r strip is keyed so that the controller and detector terminal strips cannot be reversed inadvertently.

6. Guide a three-conductor, shielded cable, or three wires in conduit through the top conduit hub of the junction box.

7. Pull out the controller terminal strip, and connect the three wires to the terminal strip as follows (see Figure 4).

• Connect the positive wire to the PWR/SIG “+” terminal.

• Connect the signal wire to the PWR/SIG “S” terminal.

• Connect the negative wire to the PWR/SIG “-” terminal.

CAUTION: If shielded cable is used, leave the cable shield’s drain wire disconnected and

insulated at the transmitter. You will connect the opposite end of the cable’s drain wire to the controller’s chassis (earth) ground.

8. Reinstall the controller terminal strip into its socket.

9. Secure the junction box cover to the junction box.

10. Route the cable or wires leading from the CO

transmitter through one of the conduit

hubs at the controller housing.

CAUTION: Do not route power and transmitter wiring through the same controller conduit hub.

The power cabl e may disrupt the transmission o f the transmitte r signal to the controller.

11. Connect the wires to the applicable detector/transmitter termin al strip at the controller as shown in Figure 4.

6 • 65-2397RK CO2 Transmitter

Cable sheild

Amplifier

Black

+ 24 VDC 4 - 20 mA In (S)

- (DC Ground)

Controller

SPAN

ZERO

SIG/PWR

BGW

LEL

Green

Detector Wires

White

Red

J-Box

IR CO2 Detector

Figure 4: Wiring the CO

12. If shielded cable is used, connect the cable’s drain wire to an available chassis (earth) ground at the controller. RKI controllers typically have a ground stud that can be used to ground the cable’s drain wire.

Transmitter to a Controller

65-2397RK CO2 Transm itter • 7

Start Up

This section describes procedures to start up the CO2 transmitter and place the transmitter into normal operation.

Introducing Incoming Power

1. Complete the installation procedures described earlier in this manual.

2. Verify that the power wiring to the controller is correct and secure. Refer to the controller operator’s manual.

3. Turn on power to the controller.

4. Turn on the controller.

5. Verify that the controller is on and operating properly. Refer to the controller operator’s ma nual.

NOTE: When first powered up, the transmitter will enter about a o ne minute period

time the controller’s warmup period is over.

transmitter’s 4-20 mA signal should be stable by the

CAUTION: Allow the detector to warm up for 5 minutes before you continue with the next

section, “Setting the Zero Signal”.

Setting the Zero Signal

Since there is a background of CO2 in air of typically 300 - 600 ppm (0.03 - 0.06 %volume), it is necessary to use a calibration kit with a 100% nitrogen cylinder to set the zero signal of

a CO

transmitter with a low range detector. Fresh air can be used to zero th e transmitter

if a 0-50 %volume or 0-100 %volume detector is being used.

WARN ING: Do not remove the junction box cover while the circuits are energized

unless the area is determined to be non-hazardous. Keep the junction box cover tightly closed during operation.

The procedure below describes applying 100% nitrogen using a calibration kit that includes a calibration cup, calibration gas, sample tubing, and a fixed flow regulator with an on/off knob. RKI Instruments, Inc. recommends using a 0. 5 LPM (liters per minute) fixed flow regulator.

1. Unscrew and remove the junction box cover from the junction box.

2. Set a voltmeter to measure in the millivolt (mV) range.

3. Plug the voltmeter leads into the test points on the amplifier. Plug the positive lead into the red (+) test point; plug the negative lead into the black (-) test point.

4. Screw the calibration cup onto the bottom of the IR CO

5. Screw the regulator into the 100% nitrogen calibration cylinder.

6. Use the calibration kit sample tubing to connect the regulator to the calibration cup.

8 • 65-2397RK CO2 Transmitter

detector .

7. Turn the regulator’s on/off knob counterclockwise to open it. Gas will begin to flow.

8. Allow the gas to flow for one minute.

9. Verify a voltmeter reading of 100 mV (±2 mV).

10. If necessary, use a small flat-blade screwdriver to adjust the zero pot until the

11. Turn the regulator’s on/off knob clockwise to close it.

12. Unscrew the calibration cup from the detector.

13. Unscrew the regulator from the 100% nitrogen calibration cylinder. For convenience,

14. Store th e components of the calibration kit in a safe and convenient place.

15. Remove the voltmeter leads from the test points.

16. Secure the junction box cover to the junction box.

Maintenance

This section describes maintenance procedures. It includes preventive maintenance, troubleshooting, and component replacement procedures.

voltmeter reading is 100 mV (±2 mV).

leave the sample tubing connected to the regulator and the calibration cup.

Preventive Maintenance

This section describes a preventive maintenance schedule to ensure the optimum performance of the CO

Daily

Verify a display reading at the controller of the background concentration of CO background concentrations of CO depending on location. The 0-5,000 ppm and 0-5 %vol ume detectors will display a r eading

in a fresh air environment because they have low ranges. The 0-50 %volume and 0-100% volume detectors will not display a reading in fresh air because their ranges are too large. Investigate significant changes in the display reading.

Monthly

This procedure describes a test to verify that the CO target gas.

WARN ING: The controller is not an acti ve gas monitoring device during the response

test procedure.

NOTE: Performing a response test on the CO2 transmitter may cause alarms. Be sure to

put the controller into its calibration mode or disable external alarms before performing this test.

transmitter. It includes daily, monthly, and biannual procedu res.

. Typical

vary from abou t 300 to 600 ppm ( 0.03 to 0 .06 %volu me)

transmitter responds properly to the

NOTE: The following procedure assumes the use of a calibration kit which includes a

calibration gas cylinder, a 0.5 LPM fixed flow regulator with an on/off knob, a calibration cup for the detector, and a length of sample tubing.

65-2397RK CO2 Transm itter • 9

Preparing for the response test

1. Place the controller into its calibration mode or disable external alarms.

2. Verify that the controller disp lay reading for the channel you are testing is consistent with typical background levels of CO

If the display reading is not consistent with typical ba ckgrou nd levels of CO

, set the

zero reading of the transmitter as described in “Start Up” on page 8 of this manual, then continue this procedure.

3. Screw the regulator into the calibration cylinder.

4. Screw the calibration cup onto the bottom of the detector.

5. Use the calibration kit sample tubing to connect the regulator to the calibration cup.

6. Set a voltmeter to measure in the millivolt (mV) range.

7. Plug the voltmeter leads into the test points on the amplifier. Plug the positive lead into the red (+) test point; plug the negative lead into the black (-) test point.

8. Use the following formula to determine the correct test points output for the test sample.

Output (mV) = (calibrating sample/fullscale) X 400 + 100

For example, with a test sample of 2.5 %Vol. and a fullscale setting of 5 %Vol., the correct output is 300 mV.

300 (mV) = (50/100) X 400 +100

Performing the response test

1. Turn the regulator’s on/off knob counterclockwise to open the regulator. Gas will begin to flow.

2. Allow the gas to flow for one minute.

3. Verify that the reading is within ± 20% of the response reading you determined earlier.

NOTE: If the reading is not within ± 20% of the correct response reading, calibrate the

transmitter as described in “Calibration” on page 16 of this manual.

4. Turn the regulator’s on/off knob clockwise to close the regulator.

5. Unscrew the regulator from the calibration cylind er.

6. Unscrew the calibration cup from the detector.

NOTE: For convenience, leave the regulator and calibration cup connected by the

sample tubing.

7. Remove the voltmeter leads from the am plifier test points.

8. Reinstall the junction box cover.

9. When the controller display reading falls below th e alarm setpoints, return the controller to normal operation.

10. Store the components of the calibration kit in a safe place.

Biannually

Calibrate the CO

10 • 65-2397RK CO2 Transmitter

transmitter as described in “Calibration” on page 16 of this manual.

Troubleshooting

The troubleshooting guide describes symptoms, probable causes, and recommended action for problems you may encounter with the CO

NOTE: This troubleshooting guide describes transmitter problems only. See the

controller operator’s manual for problems you may encounter with the controller.

Table 2:Troubleshooting the CO2 Transmitter

Condition Symptom(s) Probable Causes Recommended Action

transmitter.

Fail Condition • Controller indicates a

Slow or No Response/ Difficult or Unable to Calibrate

fail condition.

• Transmitter re sponds slowly or does not respond to response test.

• Unable to accurately set the zero or response reading during calibration.

• Transmitter requires frequent calibration.

Note: Under “normal” circumstances, the transmitter requires calibration once every 6 months.

Some applications may require a more frequent calibration schedule.

• The transmitter wiring is disconnected or misconnected.

• The wiring from the detector to the amplifier is disconnected or misconnected.

• The plug-in sensor is not properly plugged into the three-socket pattern in the detector housing body.

• The transmitter’s zero reading is low enough to cause a fail condition.

• The transmitter is malfunctioning.

• The calibration c ylinder is low, out-dated, or defective.

• The calibration gas is not an appr opriate concentration.

• The membrane on the detector housing cap is blocked with dirt or some other particulate matter.

• The transmitter is malfunctioning.

1. Verify that the transmitter wiring to the controller is correct and secure.

2. Verify that the wiring f rom the detect or to the amplifier is correct and secure.

3. Confirm that the plug-in sensor is properly installed.

4. Perform a zero adjustment. A full calibration is recommended.

5. If the fail condition continues, replace the sensor as described later in this section.

6. If the fail condition continues, contact RKI for further instruction.

1. Verify that the calibration cylinder contains an adequate supply of a fresh test sample.

2. Check the face of the detector housing cap and remove any particulate contamination from the hydrophobic membrane if necessary.

3. Verify that the calibration gas concentration is appropriate for the transmitter.

4. If the calibration/response difficulties continue, replace the sensor as described later in this section.

5. If the calibration/response difficulties continue, contact RKI for further instruction.

65-2397RK CO2 Transmitte r • 1 1

Replacing Components of the CO2 Transmitter

This section includes a procedure to replace the hydrophobic membrane, a procedure to replace the plug-in IR CO

assembly, and one to replace the amplifier. In most cases, it is not necessary to replace the entire detector assembly.

Replacing the Hydrophobic Membrane

1. Turn off the controller.

2. Turn off or unplug incoming power to the controller.

3. Unscrew the detector housing cap from the detector housing body.

4. Gently pry up the edge of the white hydrophobic mem b rane with a small flat blade screwdriver or a similar tool.

5. Peel off the hydrophobic membrane. It may be necessary to clean off the detector housing cap face to remove any residue left from the adhesive backed membrane.

6. Install the new membrane in the recess on the face of the detector housing cap.

7. Make sure the cap gasket is in place and screw the detector housing cap back onto the detector housing body.

8. Turn on the pow e r to the controller.

sensor, a procedure to replace the entire CO2 detector

9. Turn on the controller and place it into normal operation.

NOTE: When first powered up, the transmitter will enter about a o ne minute period

when the 4-20 mA output is stab ilizing and may be above the controller alarm points or well below zero momentarily. RKI controllers have a one minute warmup period when the controller does not display any gas reading or give any alarm indication. The combustible gas transmitter’s 4-20 mA signal should be stable by the time the controller’s warmup period is over.

Replacing the Plug-In CO

Sensor

1. Turn off the controller.

2. Turn off or unplug power to the controller.

3. Unscrew the detector housing cap from the detector housing body. Make sure not to lose the cap gasket.

4. Unplug and remove the plug-in IR CO

sensor.

5. Carefully plug the replacement sensor into the socket pattern that is located in the detector housing.

6. Make sure the cap gasket is in place and screw the detector housing cap back onto the detector housing body.

7. Turn on power to the controller.

8. Turn on the controller and place it into normal operation.

12 • 65-2397RK CO2 Transmitter

NOTE: When first powered up, the transmitter will enter about a o ne minute period

transmitter’s 4-20 mA signal should be stable by the

time the controller’s warmup period is over.

CAUTION: Allow the replacement sensor to warm up for 5 minutes before you continue with the

next step.

9. Calibrate the transmitter as described in “Calibration” on page 16.

Replacing the IR CO

Detector

NOTE: In most cases it is only necessary to replace the IR CO2 plug-in sensor.

1. Turn off the controller.

2. Turn off or unplug power to the controller.

3. Remove the junction box cover.

4. Remove the detector terminal strip from its socket.

5. Disconnect the detector leads from the detector terminal strip. Note the position of the color-coded leads as you remove them.

6. Unscrew the detector from the junction box.

7. Guide the detector leads of the replacement detector through the bottom conduit hub of the junction box, then screw the mounting threads of the detector into the conduit hub. If necessary for environmental conditions, apply thread sealant or teflon tape to the hub and/or detector threads to seal them.

8. Connect the detector leads to the detector terminal strip as shown in Table 3 below and Figure 4 on page 7 of this manual.

Table 3:Reconnecting the CO

Detector to the Amplifier

Detector Lead Detector Terminal Strip

Red LEL “R”

White LEL “W”

Green LEL “G”

Black LEL “B”

9. Reinstall the detector terminal strip into its socket.

10. Reinstall the junction box cover.

11. Turn on or plug in power to the controller.

12. Turn on the controller and place it int o normal operation.

65-2397RK CO2 Transmitte r • 1 3

NOTE: When first powered up, the transmitter will enter about a o ne minute period

transmitter’s 4-20 mA signal should be stable by the

time the controller’s warmup period is over.

CAUTION: Allow the replacemen t detector to warm up for 5 minutes before you continue with

the next step.

13. Calibrate the transmitter as described in “Calibration” on page 16 of this manual.

Replacing the Amplifier

1. Turn off the controller.

2. Turn off or unplug power to the controller.

3. Remove the junction box cover.

4. Unplug the detector terminal strip and controller terminal strip from their sockets. You may leave the wires connected to the terminal strips.

5. Unscrew and remove the screw with the flat and lock washers that secures the amplifier to the junction box.

6. Remove the old amplifier.

7. Place the new amplifier in the same position as the old amplifier. A foam gasket that orients the amplifier and keeps it from rotating is installed on the bottom of the amplifier. Make sure the amplifier is seated flat in the junction box.

8. Install the new amplifier in to the junction box with the screw, lock washer, and flat washer you removed in Step 5 above.

9. Install the detector and controller terminal strips into their socket s on the new amplifier as shown in Figure 4 on page 7 of this manual. If controller leads or detector leads were removed d uring this procedure, refer to Table 4 and Table 5 b elow.

Table 4:Reconnecting the Amplifier

to the Controller

Amplifier Controller

Terminal Strip

PWR/SIG “-” - (DC -) PWR/SIG “S” S (4 - 20 mA In) PWR/SIG “+” + 24V

Table 5:Reconnecting the CO

Detector to the Amplifier

Controller

Transm itte r Terminal

Strip (typical)

14 • 65-2397RK CO2 Transmitter

Amplifier Detector

T erminal Strip

DETECTOR “R” RED

Detector Lead

Table 5:Reconnecting the CO

Detector to the Amplifier

Amplifier Detector

T erminal Strip

DETECTOR “W” WHT

DETECTOR “G” GREEN DETECTOR “B” BLK

Detector Lead

NOTE: When a transmitter is first powered up with a new amplifier, the initial output

may be either high or below zero depending on the setting of the zero pot. Be sure to make arrangements so that this does not cause unwanted alarms.

10. Turn on power to the controller.

11. Turn on the controller and place it int o normal operation.

NOTE: When first powered up, the transmitter will enter about a o ne minute period

transmitter’s 4-20 mA signal should be stable by the

time the controller’s warmup period is over.

12. Allow the transmitter to warm-up for 5 minutes.

13. Calibrate the transmitter as described in “Calibration” on page 16 of this manual.

Calibration Frequency

Although there is no particular calibration frequency that is correct for all applications, a calibration frequency of every 6 months is adequate for most infrared CO

applications. Unless experience in a particular application dictates otherwise, RKI Instruments, Inc. recommends a calibration frequency of every 6 months.

If an application is not very demanding, for example detection in a clean, temperature controlled environment where calibration adjustments are minimal at calibration, then a calibration frequency of every 9 to 12 months is adequate.

If an application is very demanding, for example if the environment is not well controlled, then more frequent calibration than every 6 months may be necessary.

transmitter

65-2397RK CO2 Transmitte r • 1 5

Calibration

This section describes how to calibrate the CO2 transmitter. It includes procedures to prepare for calibration, set the zero reading, set the response rea d ing, and return to

normal operation.

W ARNING: The controller is not an active gas monitoring device during the calibration

procedure.

NOTE: The following procedure assumes the use of a calibration kit which includes a

calibration gas cylinder, a 100% nitrogen cylinder, a 0.5 LPM fixed flow regulator with an on/off knob, a calibration cup for the detector, and a short piece of sample tubing to connect the regulator to the calibration cup.

Prepari ng for Ca libration

1. Unscrew and remove the junction box cover.

2. Set a voltmeter to measure in the millivolt (mV) range.

3. Plug the voltmeter leads into the test points on the amplifier. Plug the positive lead into the red (+) test point; plug the negative lead into the black (-) test point.

4. Use the following formula to determine the correct test points output for the calibrating sample.

Output (mV) = (calibrating sample/fullscale) X 400 + 100

For example, with a calibrating sample of 2.5 %Vol. and a fullscale setting of 5 %Vol., the correct output is 300 mV.

300(mV) = (50/100) X 400 +100

5. Screw the calibration cup onto the detector housing.

6. Place the controller into its calibration mode or disable external alarms.

NOTE: Calibrating the CO2 transmitter may cause alarms. Be sure to put the controller

into its calibration mode or disable external alarms before continuing.

Setting the Zero Reading

Since there is a background of CO2 in air of typically 300 - 600 ppm (0.03 - 0.06 %volume), it is necessary to use a calibration kit with a 100% nitrogen cylinder to set the zero signal of

a CO

transmitter with a low range detector. Fresh air can be used to zero th e transmitter

if a 0-50 %volume or 0-100 %volume detector is being used.

1. Screw the regulator into the 100% nitrogen calibration cylinder.

2. Use the calibration kit sample tubing to connect the regulator to the calibration cup.

3. Turn the regulator’s on/off knob counterclockwise to open the regulator.

4. Allow the gas to flow for one minute and verify a reading of 100 mV (±2 mV). If necessary, use the zero pot on the amplifier to adjust the reading to 100 mV (±2 mV).

5. Turn the regulator’s on/off knob clockwise to close the regulator.

16 • 65-2397RK CO2 Transmitter

6. Unscrew the regulator from the zero air calibration cylinder.

7. Leave the sample tubing connected to the regulator and the calibration cup.

Setting the Response Reading

1. Screw the regulator into the calibration cylinder. Verify that the calibration gas is representative of the transmitter’s target gas.

2. Turn the regulator’s on/off knob counterclockwise to open the regulator.

3. Allow the calibration gas to flow for one minute and verify that the reading matches the response reading (±2 mV) you determined ea rlier. If necessary , use the span pot on the amplifier to adjust the reading to match the correct response reading.

4. Turn the regulator’s on/off knob clockwise to close the regulator.

5. Unscrew the regulator from the calibration cylind er.

Returning to Normal Operation

1. Remove the voltmeter leads from the am plifier test points.

2. Unscrew the calibration cup from the detector.

NOTE: For convenience, leave the regulator and calibration cup connected by the

sample tubing.

3. Secure the junction box cover to the junction box.

4. When the controller display reading falls below th e alarm setpoints, return the controller to normal operation.

5. Verify that the co ntroller display reading decreases and stabilizes at a typical background CO

reading in a fresh air environment because they have low ranges. The 0-50 %volume and 0-100 %volume detectors will not display a reading in fresh air because their ranges are too large.

6. Store the components of the calibration kit in a safe and convenient place.

level. The 0-5,000 ppm and 0-5 %volume detectors will display a

65-2397RK CO2 Transmitte r • 1 7

Parts List

Part Number Description

06-1248RK Sample tubing (3/16 in. x 5/16 in.; specify length when ordering ) 07-0039RK Detector housing cap gasket 18-0400RK-01 Junction box with spacers 33-0157RK Hydrophobic disk membrane for detector cap 57-1053RK Amplifier with gasket (specify detector part number when ordering)

Table 6 lists replacement parts and accessories for the CO2 transmitter.

Ta ble 6: Par ts List

61-5040RK-02 CO 61-5040RK-03 CO 61-5040RK-05 CO 61-5040RK-10 CO 65-2397RK-02 CO 65-2397RK-03 CO 65-2397RK-05 CO 65-2397RK-10 CO 71-0185RK 65-2397RK CO 81-0070RK-01 Steel calibration cylinder, 2000 ppm CO 81-0072RK-01 Steel calibration cylinder, 2.5% CO 81-0073RK-01 Steel calibration cylinder, 15% CO

replacement plug-in sensor, 0-5,000 ppm

replacement plug-in sensor, 0-5% Volume

replacement plug-in sensor, 0-50% Volume

replacement plug-in sensor, 0-100% Volume

transmitter, 0-5000 ppm, (includes detector, junction box, and amplifier)

transmitter, 0-5% V ol ume, (inc lud es detec tor, junction box, and amplifier)

transmitter, 0-50% Volume, (includes detector, junction box, and amplifier)

transmitter, 0-100% Volume, (includes detector, junction box, and amplifier)

Transmitter Operator’s Manual (this document)

, 34-liter

81-0078RK-01 Steel calibration cylinder, 100% nitrogen, 34-liter 81-1050RK Regulator, 0.5 liter/minute; with pressure gauge and flow control knob, for 17 liter

and 34 liter steel calibration cy lin der s 81-1117RK Calibration cup 82-0006RK Pot adjust screwdriver, for calibration

18 • 65-2397RK CO2 Transmitter

RKI Instruments 65-2397RK User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual